What are the similarities between the onion and white fish cells?

Both cells have eukaryotic origins
both cells possess a nucleus
both cells organelles are membrane bound

The rate that would change would be the  searching efficiency/attack rate. there are only two other rates in this model: the  growth rate of prey, and the  predator or consumer mortality rate.the  searching efficiency/attack rate is what indicates how effectively can a predator capture its prey whether in the searching process or actual capturing/attacking process.